This application claims priority of DE 199 06 334.6, filed Feb. 16, 1999, and DE 199 14 657.8, filed Mar. 31, 1999, the disclosures of which are expressly incorporated by reference herein.
The invention relates to a sliding roof for vehicles of the type which is movable in a power driven manner from a closed position to an open position in a first moving direction and to a lifted position in a second moving direction.
In connection with sliding roofs for vehicle, it is generally known that these sliding roofs can be moved from a closed position, on the one hand, into an open position and, on the other hand, into a lifted position. In this case, the cover of the sliding roof reaches a closed position from two directions, specifically from the lifted position coming from above and from the open position coming from below.
Such a sequence of movements leads to the problem that even if the slack is taken into account, when calculating the position of the sliding roof, because of the remaining elasticities in the sliding roof drive, the closed position cannot be reached in a precisely reproducible manner. Particularly if the closed position has been reached from the open position, it is not identical with the closed position reached from the lifted position.
It is an object of the invention to provide a sliding roof of the above-mentioned type in the case of which the closed position can be precisely reproduced.
According to the invention, this object is achieved by providing an arrangement wherein the closed position is always approached from the same moving direction. It is suggested according to the invention to approach the closed position always only from a single selected moving direction. As the result of this measure, the influence of the transmission slack and the elasticities in the drive of the sliding roof is suppressed, and the cover reaches the same position during each final closing operation. This advantageously improves the visual effect of the vehicle and the cover of the sliding roof can be aligned such in the closed position that the wind noise generated when the cover is closed by the gap surrounding the cover is minimized. As the result of the invention, in one embodiment, the position tolerance of the cover in its closed position could be improved from 1.5 mm to 0.1 mm. In addition, the invention can be implemented in a simple manner by the corresponding programming of a control unit and particularly without high-expenditure additional mechanical measures.
As a further development of the invention, it is also suggested that, during a closing operation from the non-selected moving direction, the closed position is approached by driving and subsequently from the selected moving direction.
It is also suggested to ensure that the cover of the sliding roof, when moving through the closed position, is not moved out of an opening of the sliding roof. This prevents that, when the cover dips through the closed position, a gap is formed at the edge of the cover which may result in disturbing wind noise and may also cause pressure changes in the vehicle interior.
Finally, it is suggested that the closing operation be automatically carried out from the non-selected moving direction as soon as the closed position has been reached the first time. According to this construction, the dipping-through of the cover will also be carried out when the user releases an actuating switch for the sliding roof, as soon as the cover reaches its closed position for the first time. Particularly in conjunction with the above-mentioned construction, such an operation can be carried out without any risk since, during this automatically occurring movement, no gap is formed into which fingers or objects can be squeezed.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.